The present invention relates generally to the field of virtual reality systems and methods and more specifically to handheld systems operating as interactive virtual portals.
As processing power and display capabilities of computers continue to evolve, new applications for them are discovered. One such application area is that of virtual experiences, also known as virtual reality. Virtual reality is used to describe the simulation of real world scenes and scenarios using a computer and a display device. Virtual scenes are often incorporated into video games, marketing presentations, in work place and living environment simulations, and training materials. As used herein, virtual reality will be used to describe the simulation of real world scenes and images using a display device and real world will be used to describe scenes and images as they appear to a user if viewed in real life.
Although display and processing innovations have been used to improve virtual reality experiences for the user, they often fail to realistically duplicate the real world scenes and experiences being simulated. As such, a user's experience is not optimized. Limitations associated with prior art virtual reality systems may take many forms. For example, display devices are often too large to be moved by a user while engaged in a virtual reality session or they are attached to an essentially immovable structure such as a desk. By way of example, the Gimbal-Mounted Virtual Reality Display System disclosed in U.S. Pat. No. 6,094,180 employs a display mounted to a desk using supporting legs. The supporting legs are designed to flex as a user physically manipulates the display housing while engaged in a virtual reality session. Although the display may be displaced slightly while connected to the legs, it cannot be readily transplanted to a new location during a virtual reality session. As a result, a user's experience is not optimized while engaged in virtual reality sessions using the invention disclosed in U.S. Pat. No. 6,094,180.
In other prior art systems, the user interface to the system is cumbersome. For example, U.S. Pat. No. 5,436,638 discloses a means for yoking the viewpoint orienting muscles of the user as a way of getting user inputs into the computer. The yoking system is attached to a structure such as a desk and therefore constrains a user to a single location while engaged in a virtual reality session.
Attempts have been made to eliminate encumbrances associated with fixed displays and uncomfortable user interfaces, such as yoking devices, using holographic representations, portable displays, and motion tracking systems installed in rooms where virtual reality sessions are performed. However, these approaches also have their respective shortcomings. For example, U.S. Pat. No. 6,031,519 generates a holographic image that can be interacted with by a user; but, interaction with the image requires that the user remain in a single location, such as a chair, that is preferably within an arm's length of the displayed image. Thus, a user is essentially immobile while using the invention described in U.S. Pat. No. 6,031,519.
U.S. Pat. No. 5,910,797 employs a portable display employing a gravitational sensor for controlling screen orientation and for imparting an acceleration to a displayed object as a function of display movement. User control of an image may be further enhanced through the use of a joystick such as when a ball is moved through a maze as part of a video gaming session. Although the apparatus of U.S. Pat. No. 5,910,797 enables a user to remain mobile, it does not maximize the user's experience because the apparatus does not maintain the perspective that the user would have if viewing the same image in the real world. For example, if the user views an image of a house using the apparatus of U.S. Pat. No. 5,910,797, movement of the display imparts an acceleration to the displayed image even though the image may not appear to move if seen in the real world. This result would occur if the user moved from one location to another while viewing the house even if the user's movement would have had the effect of taking him from the front of the house to the side of the house if he were viewing the house in the real world. As such, the apparatus of U.S. Pat. No. 5,910,797 does not retain the real world viewpoint for a user while engaged in a virtual reality session using the invention.
Fixed-in-place motion tracking systems (FIP systems) such as the IS-600 marketed by InterSense may be installed in facilities where virtual reality sessions will take place. FIP systems normally attach to the ceiling of a room and comprise one or more transponder units for sending and receiving signals to a device such as a virtual reality headset worn by a user. In addition, FIP systems normally employ a processing system for controlling the transponder units and headset. FIP systems have several disadvantages associated with them. First, they require modifications to facilities where virtual reality sessions will occur because they must be installed above, or around, the area where a user will partake in virtual experiences. Therefore, virtual sessions are limited to the room, or rooms, where the equipment is installed thus limiting the types of virtual sessions employed. Second, special processing hardware is normally required to drive the transponder units mounted on ceilings and/or walls. Since processing hardware normally requires A/C power from a wall outlet, it is normally sized in such a way that it is not readily transportable. Third, software applications and images may not be readily available for the system because they must be customized to work with a particular FIP system. As a result of the above-mentioned shortcomings, widespread use of FIP systems is inhibited and user experiences are not optimized.
There exists a need for a handheld virtual reality display system for providing a user with freedom of movement while at the same time maintaining the perspective that the user would have if viewing a displayed image in the real world. The system should function as a portal, or window, in that it provides a user with ability to see displayed images, or virtual representations, while moving about a space with which the displayed images are associated.